56 unexposed groups. The people appeared to have less hypertension on the whole than is noted in people in the continental United States. An artaritis survey Showed no great differences be- on the assimilation, excretion, and bodyburdenof radionuclides. tween the exposed and the unexposed people, and amiurtations in 1959 and 1960 were, for the most populations. Medical histortes of the intervals between the ex- part, uneventful and revealed no major epidemics of disease. Several deaths had occurred and new births were reported. In the exposed group, two deaths occurred and in the unexposed group, three. Two of the latter were due to influenza acquired during an epidemic on Kwajalein. The four deaths that have occurred in the exposed people since exposure represent a mortaiity rate of 8.1 per 1000 population, compared with 8.3 for the comparison population and 6.8 for the Marshall Islands as a whole. A review of the birth rate of the exposed group over the past 6 years seems to indicate no noticeable effect of their expo- sure on fertility. The 24 births represent a rate of 48 per 1000 population, compared with 37.3 for the Marshall Islands (1957). The 20 births over a 3-year period for the comparison population represent a rate of 62 per 1000 population. A somewhat greater incidence of miscarriages and stillbirths has been noted in the exposed women, but be- cause of the paucity ofvital statistics in the Marshallese and the small numberof people involved, the data are not readily amenable to statistical analysis. Physical examinations showed the exposed and the unexposed people to be generally in a state of good health. No diseases were noted that could be directly related to radiation effects. The incidence of various disorders in both adults and children was about the same in the exposed and unexposed groups. In connection with growth and development studies, a project on the verification of accuracy ofages of the children has not been completed and,therefore, the suggestive evidence previously presented of possible lag in statural growth in the exposed children must await confirmation. It was notech however, that in the 6-year chronological age group, three boys and onegir! out offive boys and two girls in the exposed group exhibited signifi- cantly retarded skeletal maturation as judged by X-ray examination. The birth dates of these children seemed to befairly well established. about the same incidence as is seen in American An ophthalmological survey showed no remarkable differences between the exposed and unexposed groups except possibly a slightly greater number of cases of pterygii, pingueculae, and cornealscars in the exposed group. It is not know whetherthis finding is of any significance in relation to their radiation exposure. Slit-lamp observations showed no opacities of the lens characteristic of radiation exposure. As a whole, visual and accomodation levels in the Marshallese appeared to be above the average in the U.S. population. A dental survey showed nosignificant differences in either caries rate or incidence of peridontaldisease between exposed and unexposed groups. The poor oral hygiene generally observed in the Marshallese had its usual results, namely, high caries rate in teen-age children, severe peridontal lesions in adults (heavy calculus and loss of alveolar bone), and edentulous mouthsin the aged. Radiation exposure did not appear to haveaffected developing dentition in the exposed children. Late effects ofradiation. Various parameters usually associated with aging were measured orestimated on a 0 to ++ scale (skin looseness, elasticity, and senile changes; greying of the hair and balding; accomodation, visual acuity, and arcus senilis; hearing; cardiovascular changesincluding blood pressure and degrees of peripheral andretinal arteriosclerosis; neuromuscular function; and hand strength). Comparison of these measurements mn exposed and unexposed individuals of the same age groups showed no apparent differences. A biological age score was calculated for indiviuals and groups by use of an average percentage score. Life shortening effects of radiation have not been apparent. As noted, the mortality rate was about the same in the exposed as in the unexposed people. The one case of cancer that developed in the exposed group occurred at 5 years after exposure, too soon, itis believed, to bear any particularrelation to radiation exposure. Leukemta surveys including physical findings, studies of white cell A gard to any possible late developingeffects of their exposure, their hematological status, and the influence of the slightly contaminated environment A cardiovascular survey of the adults showed no outstanding differences between the exposed and # posed comparisaapopulation, particularly in re- es ad — we - Maen. status of the people in relation to that of the unex- e